update

Please have a look here Email notification of replies pertaining to me for more insight.

Especially Re^3: Email notification of replies pertaining to me (work)

If you are willing to write some javascript, you can popup a notification when you check the website. Then, just let the site reload every x minutes, via js or a plugin.

I wrote a script for woot messages. Rudimentary and just checks a number. But it shows that it is relatively easily, as that was only four line of actual code. You ought to be able to get something to check the XP Nodelet, at the very least.

This would cause much traffic, which tye would prefer to avoid.

If I had a clear concept how to identify bouncing emails I could provide a script I wrote for $.

But this would also imply the need for disabling and reactivating an address.

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!}

This would cause much traffic

Only if everyone did it, and then at a high rate. I would figure refreshing (automatically) once ever 15 minutes would suffice, and not cause much hurt to the server.

Does that make sense?

Btw what's the benefit of this JS solution over msg notification combined with the CB sidebar?

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!}

update

I'm aware that the CB Sidebar somehow contradicts the traffic argument.

With JS, the tab does not need to be in front of you. You can be doing something else when an alert of some form of message pops up.